XProfan

Quelle:  [...] 
Win9x erlaubt alle Schnittstellen-Nummern.
NT erlaubt nur Nummern von Schnittstellen die aktuell präsent sind.
/* Win NT sets the flow control members based on (or lack of) the last
parameter.  Win 9x does not set these members. */
/* Win NT sets the fDsrSensitivity member based on the idsr parameter.
Win 9x sets fOutxDsrFlow instead. */
/* Set DCBlength. (Windows NT does not do this, but 9x does) */
lpdcb->DCBlength = sizeof(DCB);
/* Make a copy of the original data structures to work with since if
there is an error in the device control string the originals
should not be modified (except possibly DCBlength) */
memcpy(&dcb, lpdcb, sizeof(DCB));
Quelle:  [...] 
996 typedef struct tagDCB
997 {
998     DWORD DCBlength;
999     DWORD BaudRate;
1000     unsigned fBinary               :1;
1001     unsigned fParity               :1;
1002     unsigned fOutxCtsFlow          :1;
1003     unsigned fOutxDsrFlow          :1;
1004     unsigned fDtrControl           :2;
1005     unsigned fDsrSensitivity       :1;
1006     unsigned fTXContinueOnXoff     :1;
1007     unsigned fOutX                 :1;
1008     unsigned fInX                  :1;
1009     unsigned fErrorChar            :1;
1010     unsigned fNull                 :1;
1011     unsigned fRtsControl           :2;
1012     unsigned fAbortOnError         :1;
1013     unsigned fDummy2               :17;
1014     WORD wReserved;
1015     WORD XonLim;
1016     WORD XoffLim;
1017     BYTE ByteSize;
1018     BYTE Parity;
1019     BYTE StopBits;
1020     char XonChar;
1021     char XoffChar;
1022     char ErrorChar;
1023     char EofChar;
1024     char EvtChar;
1025     WORD wReserved1;
1026 } DCB, *LPDCB;